- Available in 10 pF, 100 pF,1000 pF, 5000 pF, 10,000 pF
- New 5 nF and 10 nF standards available
- A national laboratory standard
- For calibrating working standards
- Standard for dissipation factor
- 5 year warranty included
GenRad 1404 Series Primary Standard Capacitors1404 GenRad
GenRad 1404 Primary Standard Capacitors
Applications
- Primary capacitance standard
- Standard of dissipation factor
- Charge calibration
- dc current calibration
Overview
The GenRad 1404 Series is the standard of choice in metrology labs and is still used today by national metrology institutes (NMIs) around the world. These capacitors were designed as primary reference standards of capacitance, against which working standards can be compared. IET Labs continues to manufacture them to the same exacting specifications that GenRad used in 1963.
The 1404 has also been used in systems that generate low dc currents, as described in the paper “Generation of reference dc currents at 1 nA level with the capacitance-charging method”. Combined with an accurately known external resistor, a 1404 becomes a standard of dissipation factor.
Construction
- Invar plate assembly: all critical parts of the plate assembly are made of Invar, which gives stability and a low temperature coefficient.
- Sealed brass container: after heat cycling and adjustment, the assembly is mounted in a heavy brass container. The container is evacuated, filled with dry nitrogen at a pressure slightly above atmospheric, and sealed.
- Protective housing: the container is mounted on an aluminum panel and protected by an outer aluminum case.
- Temperature cycling: each capacitor goes through a series of temperature cycles to determine hysteresis and temperature coefficients and to stabilize the capacitance.
More information on the design and frequency characteristics is in the GenRad Experimenter, August 1963 (1404 Capacitance Standard).
Calibration
- Direct measurement: each 1404 is calibrated on an Andeen-Hagerling AH2700A Capacitance Bridge. The measurements are traceable to the SI through an NMI (NIST), with a CMC as good as 5.5 µF/F.
- Accredited calibration by transfer: IET Labs can also provide accredited calibration using the GenRad 1620, by transfer measurements against 1404 standards. These standards are traceable to the SI mainly through NRC in Canada, with a CMC as good as 4.8 µF/F.
For details, see the IET Labs Capacitance Calibration page.
Models
| Model | Capacitance | Note |
|---|---|---|
| GenRad / General Radio 1404-10nF | 10 nF (10,000 pF) | Recently released |
| GenRad / General Radio 1404-A | 1000 pF | Primary standard capacitor |
| GenRad / General Radio 1404-B | 100 pF | Primary standard capacitor |
| GenRad / General Radio 1404-C | 10 pF | Primary standard capacitor |
